Beamforming is a method for using wireless channel state information to transmit signals to the receiver in order to improve reception quality, and increase data throughput in a Multi-In, Multi-Out (MIMO) communication system. Implicit beamforming is a class of beamforming techniques that do not require the explicit cooperation of the receiving device to learn the channel state information. However, in order to optimize implicit beamforming, the transmit and receive paths of the beamforming device should be calibrated. Previous schemes to calibrate the transmit path of a device involve the conditioning the device to transmit a calibration signal, capturing the transmission with specialized calibrated equipment and analyzing the signal to determine the transmit compensation parameters.
Similarly, calibrating the receive path involves using specialized, calibrated equipment to generate a calibration signal, injecting it into the receive path of the device and analyzing the receive signal in the device to determine the receive compensation parameters.
Another scheme may involve the addition of hardware to the device to loop the transmit signal back to the receiver. The device would be conditioned to transmit a calibration sequence and the looped back signal would be analyzed in the receiver to determine the compensation parameters. If the calibration is stable for the lifetime of the device the calibration could be done once during its manufacture. If the calibration is not stable it is necessary to perform the calibration again when conditions change.
Accordingly, what is desired is to provide a system and method that overcomes the above issues. The present invention addresses such a need.